Electro-convulsive therapy (ECT) system with enhanced safety features

Abstract

An electro-convulsive therapy (ECT) system includes both hardware and software safety detectors and monitors, including a pulse generator that generates a pulse train of a plurality of pulses with parameters specified by the user. The safety monitors monitor these user-specified parameters as well as other important pulse parameters both during treatment of a patient and prior to treatment in order to ensure that the system is operating according to specification and, therefore, will not injure the patient. The pulse generator is responsive to the safety monitors in that if any of the safety detectors detect a parameter that is out of tolerance, the safety monitor disables the pulse generator so that no further pulses are delivered to the patient. The safety detectors detect plurality of pulse characteristics including pulse width, frequency, voltage, current, treatment duration, as well as energy. In addition to these real time safety checks, the system includes a pre-treatment arming routine that applies a pre-treatment ECT pulse train to an internal load and monitors these same parameters during this internal test. If all of these parameters are within tolerance, the system moves to an armed state in which the user can proceed to apply an ECT treatment pulse train. If any one of these safety checks fails, however, the system does not arm and, therefore, prohibits treatment.

We claim: 
     
       1. A method of ensuring the safety of a patient during electro-convulsive therapy (ECT) by automatic self test and operation of ECT apparatus, the method comprising: applying a pre-treatment pulse train to a dummy load including a plurality of individual pre-treatment pulses, each pre-treatment pulse having pulse parameters that define the pulse, the pulse parameters defining a set of pulse train parameters;   measuring a pulse train parameter of the pre-treatment pulse train across the dummy load; and   applying a treatment pulse train to the patient only if the measured pulse train parameter satisfies a predetermined criteria; and   disabling the apparatus from applying the treatment pulse train to the patient if the measured pulse train parameter fails the predetermined criteria.   
     
     
       2. A method of ensuring the safety of a patient during electro-convulsive therapy (ECT) according to claim 1 wherein the step of measuring a pulse train parameter includes the step of measuring a pulse width of a pre-treatment pulse. 
     
     
       3. A method of ensuring the safety of a patient during electro-convulsive therapy (ECT) according to claim 1 wherein the step of measuring a pulse train parameter includes the step of measuring a frequency of the pre-treatment pulse train. 
     
     
       4. A method of ensuring the safety of a patient during electro-convulsive therapy (ECT) according to claim 1 wherein the step of measuring a pulse train parameter includes the step of measuring a duration of the pre-treatment pulse train. 
     
     
       5. A method of ensuring the safety of a patient during electro-convulsive therapy (ECT) according to claim 1 wherein the step of measuring a pulse train parameter includes the step of measuring a power of the pre-treatment pulses. 
     
     
       6. A method of ensuring the safety of a patient during electro-convulsive therapy (ECT) according to claim 5 wherein the step of measuring a power of pre-treatment pulses includes: measuring a voltage of a pre-treatment pulse;   measuring a current of the pre-treatment pulse; and   multiplying the measured current and the measured voltage to produce the measured power.   
     
     
       7. A method of ensuring the safety of a patient during electro-convulsive therapy (ECT) according to claim 6 wherein the step of measuring a pulse train parameter includes the step of measuring an energy of the pre-treatment pulse train. 
     
     
       8. A method of ensuring the safety of a patient during electro-convulsive therapy (ECT) according to claim 7 wherein the step of measuring an energy of the pre-treatment pulse train includes integrating the measured power. 
     
     
       9. A method of ensuring the safety of a patient during electro-convulsive therapy (ECT) according to claim 8 wherein the step of integrating the measured power includes: converting the measured power to a power signal having a frequency proportional to the measured power; and   incrementing a counter by the power signal to produce a count signal that is proportional to the measured energy.   
     
     
       10. A method of ensuring the safety of a patient during electro-convulsive therapy (ECT) according to claim 1 further comprising: applying a train of treatment pulses to a patient;   measuring a pulse train parameter of the treatment pulse train applied to the patient; and   terminating the treatment pulse train if the measured pulse train parameter of the treatment pulse train fails to satisfy a predetermined criteria.   
     
     
       11. A method of ensuring the safety of a patient during electro-convulsive therapy (ECT) according to claim 10 wherein the step of measuring a pulse train parameter includes the step of measuring a pulse width of the treatment pulses. 
     
     
       12. A method according to claim 10 in which each treatment pulse has a pulse width, the elapsed time of the pulse train defines a pulse train duration, and the time between adjacent pulses defines a frequency of the treatment pulse train; the measuring step includes a pulse width detection step that measures the pulse width of each applied ECT treatment pulse; and   the terminating step includes a pulse width monitoring step responsive to the pulse width to cease applying the treatment pulses to the patient if a measured pulse width exceeds a predetermined maximum pulse width.   
     
     
       13. A method according to claim 10 in which each treatment pulse has a pulse width, the elapsed time of the pulse train defines a pulse train duration, and the time between adjacent pulses defines a frequency of the treatment pulse train; the measuring step includes a pulse train duration detection step that measures the duration of the applied ECT treatment pulse train; and   the terminating step includes a pulse train duration monitoring step responsive to the pulse train duration to cease applying the treatment pulses to the patient if the measured pulse train duration exceeds a maximum pulse train duration.   
     
     
       14. A method according to claim 10 in which each treatment pulse has a pulse width, the elapsed time of the pulse train defines a pulse train duration, and the time between adjacent pulses defines a frequency of the treatment pulse train; the measuring step includes a pulse train energy detection step that measures the energy in the applied ECT treatment pulse train; and   the terminating step includes a pulse train energy monitoring step responsive to the pulse train energy to cease applying the treatment pulses to the patient if the measured pulse train energy exceeds a predetermined limit.   
     
     
       15. A method according claim 14 wherein the step of pulse train energy detection includes: a power detection step that generates a power signal having a signal level corresponding to the power of each applied ECT treatment pulse; and   an integration step receiving the power signal and generating an energy signal corresponding to the level of energy of the applied ECT treatment pulse train.